We have recently discovered that thebaine forms an anion which is protonated and alkylated at C5, this discovery should make possible the synthesis of a number of C5 alkyl analogs of such important substances as hydrocodone, oxymorphone, naloxone, naltrexone, etrophine, diprenorphine, codeine and morphine, and should also make available, by carbonation, the corresponding 5-carboxylic acid from which a number of interesting conjugates with alpha-amino acids might be derived, and we propose to synthesize such substances. We have already shown that 5-methylthebaine can easily be converted into 14-hydroxy-5-methylcodeinone, the key intermediate for the preparation of t-methyloxymorphane, nalaxone and naltrexone, and have also shown that 5-methylthebaine undergoes the Diels-Alder reaction with methyl vinyl ketone.